What inserts for a NVTGL-12c tool holder?

[mike-sid]

I have an old obsolete Valenite tool holder. It is marked NVTGL-12C, what inserts does it take? It has a triangle one on it now. I also have a box of TD 6P inserts, do they go together?
Mike

[PixMan]

Think you could post a couple of photos of the tool and the inserts, Mike? I have a lot of old Valenite catalogs but can't find anything close, and these catalogs go back as far as 1986.

[mike-sid]

Here they are

[PixMan]

Now that's strange. I've never seen a negative rake TNMG insert using a mechanical chipbreaker before. I really don't believe that holder should be using one of those inserts.

Loosen that top clamp and remove the insert. If there's no eccentric screw in the center to engage the hole in the insert, the carbide seat under it is screwed down with a countersunk hex socket screw and the walls of the pocket have clearance angles, that means the holder is for TPG43x size & style inserts. At least that's my best guess based upon the style of holder being similar to ones I have, but for slightly smaller and more common TPG32x inserts.

If the holder is as I suspect, the insert is held flat and parallel to the top and bottom of the holder body. If it were a holder for negative rake TNMG's, it would hold the insert tipped downward at -5º.

I believe the box of ten "inserts" are actually replacement seat/shims, and may or may not be for that holder. It's easy to compare once you have that insert out.

[mike-sid]

here's a picture,

[PixMan]

Thanks for posting that photo, Mike. It does appear to be as I said. If you look at the pocket for the insert from the side, is that carbide seat sitting flat, parallel to the top and bottom of the holder? If so, that definitely a holder for TPG43x inserts. I have the two smaller sizes, TPG321, TPG322, and TPG221 & TPG222.

Does the mechanical chipbreaker that's under the clamp have a little hole in it and the clamp have a matching pin on the underside which mates with the chipbreaker? That's the style my CTGPL and CTGPR 16-3 holders have for the TPG32x size inserts.

If I'm right look around for some TPG or TPU 431 or 432 inserts. Those inserts are available everywhere, you'll find good deals on eBay but do send me a link before buying so I can confirm they're good and tell what the grade is good for. The TPG inserts aren't very popular anymore because they have no chipbreaker in the top form of the insert as modern inserts do, but if you find a cermet grade those are GREAT for finishing steels, stainless steels, aluminum and just about anything else.

That TNMG insert should be tossed into your scrap carbide box if you have one.

[mike-sid]

(02-10-2015, 09:41 PM)PixMan Wrote: Thanks for posting that photo, Mike. It does appear to be as I said. If you look at the pocket for the insert from the side, is that carbide seat sitting flat, parallel to the top and bottom of the holder? If so, that definitely a holder for TPG43x inserts. I have the two smaller sizes, TPG321, TPG322, and TPG221 & TPG222.

Does the mechanical chipbreaker that's under the clamp have a little hole in it and the clamp have a matching pin on the underside which mates with the chipbreaker? That's the style my CTGPL and CTGPR 16-3 holders have for the TPG32x size inserts.

If I'm right look around for some TPG or TPU 431 or 432 inserts. Those inserts are available everywhere, you'll find good deals on eBay but do send me a link before buying so I can confirm they're good and tell what the grade is good for. The TPG inserts aren't very popular anymore because they have no chipbreaker in the top form of the insert as modern inserts do, but if you find a cermet grade those are GREAT for finishing steels, stainless steels, aluminum and just about anything else.

That TNMG insert should be tossed into your scrap carbide box if you have one.

 The chip breaker on the clamp has a hole for the pin on the clamp.  I took some more pictures of the tool holder.  I'm not exactly sure what you mean about the seat.

[PixMan]

What I mean is what it shows in the pictures from the side. Instead of being tilted downward to give clearance for that square-sided TNMG insert that was in the holder, it's flat and parallel to the tool shank and side clearance angle is part of the proper TPG43x insert. That's also confirmed by the fact that you can see the 11º angles along the sides of the insert pocket.

[mike-sid]

Gotcha. Off to ebay!